Terry t



T. T. KING.

ELECTROMAGNETIC DEVICE.

APPLICATION FILED NOV.2. 1915.

1,315,777. Patented Sept. 9, 1919.

I ll l II llllllll Inventor: Terry T. King,

His fittorneg UNITED ST E PATENT OFFICE.

TERRY T. KING, OF FOB-T INDIANA, ASSIGNOR T GENEBIAI: ELECTRIC COMPANY, A CORPORATION 01' NEW YORK.

ELECTROMAGNETIC DEVICE.

Specification of Letters Intent.

Patented Sept. 9, 1919.

- Applioation filed November 2, 1816. Serial No. 59,218.

' operation.

In its broadest aspect, my invention c om prises an electromagnetic device having a plurality of separate magnetic paths, with means tending to simultaneously induce therein a magnetic flux change, and means for normally restraining said change in all the magnetic paths but one.

It will be apparent that my invention may take a variety of forms. For example, in the particular embodiment of my invention illustrated in the drawings I have shown the electromagnetic device adapted for controlling electric circuits, and in the form illustrated this is accomplished by providing a member which is movable inresponse to flllux changes in the respective magnetic at s. p For a fuller understanding of my invention, reference may be had to the accompanying drawings, in which Figure 1 is a diagrammatic view, includin the circuit connections, of a device embo ying my invention; Fig. 2 is a front elevatlon; and

' .Fig. 3 is a side view.

Referring, now, to the drawings in which I have shown one embodiment of my invention, A is a base plate on which the device is mounted. The primary coil 10 of a transformer is connected to the supply conductors 11 and 12 of an alternating current circuit, in connection with which my invention is particularly applicable, althou h it will, of course, be understood that 't e same can be used with a pulsating unidirectional current. This coil is wound upon thecentral portion 13 of an E-shaped core B. The primary coil sets up a magnetic flux' which divides and passes through two paths formed by the two outer legs 14 and 15 of the core and an armature. 16 which is pivoted at 17 on the core. The armature'ie designed to oscillate, sufliciently to operate switch contacts, between one or the other of the legs 14 or 15 of the core and the adacent end of the armature. The Outer ends of the legs 14 and 15 and the, adjacent ends of the armature 16 are preferably wedgeshaped, as shown, and the portion of the armature which cooperates with the middle leg 13 1s preferably made with a semi-circular fit so that the air gap on the middle leg is constant, irrespective of the position of the armature. This has the effect of practically eliminating vibration or chattering at the contacting parts when the device is used on alternating current; Secondarv co1ls 19 and 20 are wound upon the legs 14 and 15, respectively, of the core. The clrcuits for these coils are controlled by a switch C, which I have here shown as comprising a helical thermostat, but which may in ractice be any form of switch, and may, if esired, be manually operated. The outer end of the thermostat 21 is attached to a pivoted arm 22, the free end of which engages contacts 23 and 24, preferably by a snap action. The contact 23 is connected to one terminal of the coil 19, and the contact 24 to one terminal of the coil 20, by conductors 25 and 26, respectively, while the other ter'minalsof these two coils are connected by conductors 27 and 28 to the thermostat. It will thus be apparent that when the end of the arm 22 is in engagement ment with the contact 24, the coil 20 is similarly included in a closed circuit. A working circuit is controlled by the movement of the armature 16 through movable contacts 29 which engage stationary contacts 30. The contacts 29 are mounted on flexible arms 31, carried by elbow levers 32, and pivoted at 33 'to brackets mounted on thebase A. The levers 32-are actuated by means of arms 34, the upper ends of which are pivoted to the levers 32 at 35, and the lower ends of which are pivoted to a cross-bar 36 secured to the upper end of the armature-16. The links 34 thus constitute, with the armature 16, Y a tog le, which, when straightened, causes the levers 32 to move anti-clockwise, as viewed in Fig. 3, and the contacts 30 to engage the contacts 29. The armature and the parts connected thereto are so arranged that normally the contacts 29 will move outwardly away from the contacts 30.

The operation of the device embodying my invention is as follows: When a circuit is closed to the primary coil 10 from the supply conductors l1 and 12, a magnetic flux is set up which passes through the two branches formed by the legs 14 and 15 ot' the core and the armature, and the relative amounts of flux in the two branches are inversely proportional to the relative reluctance of the two paths, the larger amount of flux passing through that path which has the shorter air gap, with the result that the armature will be attracted to and held tightly by one end, so that one magnetic path will have practically no air gap and a minimum magnetic reluctance, and the other a substantial air gap,for example, onequarter of an inch, and a relatively large reluctance. The preponderance of flux in one path over that in the other will, therefore, hold the armature 16 firmly in a given position. Now, the flux passing through the two magnetic circuits sets up a voltage in the secondary coils 19 and 20 proportional to the number of turns and the amount of flux. Assume, now, that the working circuit is open and the armature in the posi tion shown, and that it is desired to move the armature to the other position and close the working circuit. If, for example. my

invention is used in the manufacture of ice,

or in refrigeration, the conditions may require that the circuit to a motor be closed, and this condition will be brought about by such a change in temperature as will bring the arm 22 into engagen'ient with the contact 24. This closes a circuit through the coil 20, and a current will be set up in the coil, which, in turn, sets up a magnetic flux which is superimposed upon the flux due to the primary exciting coil 10. This flux, which opposes the main flux, weakens the pull exerted on the armature 16 between the end of the leg 15 and the adjacent end of the armature, with the result that the attraction exerted at the other end of the armature will overpower that exerted at the end adjacent the leg 15, and the armature will be tilted to bring theend of the armature into engagementwith the leg 1st. During this tilting movement, the increase in air gap at the left in Fig. 1 will still further weaken the attractionexerted by the leg 15 on the adjacent end of the armature by weakening the flux in that branch of the magnetic circuit, while the decrease in air gap between the leg 14 and the adjacent end of the armature will correspondingly increase the attraction exerted on that end of the armature, so that, once started, the armature moves quickly into its new position.

In the same manner, when the arm 22 is caused to engage the contact 28, the coil 19 is included in a closed circuit, and the armature is caused to move back into the position shown in Fig. 1. v

It is an important feature of my invention that the circuits of the secondary coils are broken at the thermostat when the current and voltage at the contacts are practically negligible. This is because the change in the position of the armature takes place before the circuit is broken at the contacts. \Vhen the armature is moved from the position shown in Fig. 1, for example, in which case the coil 20 is short-circuited, the move ment of the armature takes place before the arm 22 leaves the contact 23, so that an air gap is introduced into the n'iagnetic path of the coil 20, which serves to cut down the voltage and the current in this coil, so that when the circuit is broken at the contacts of the thermostat no sparking in practice takes place.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the ap paratus shown is only illustrative and that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An electromagnetic device, comprising a movable member having two positions, an operating winding having two magnetic cir cuits, a source of alternating current con nected to said winding for setting up a variable fiux in the respective magnetic circuits, and a winding associated with each magnetic circuit and energized at will to superimpose magnetization upon either magnetic circuit and cause the other magnetic circuit to predominate and move the member.

2. An electromagnetic device for alternating current circuits, comprising a movable member having two positions, an operating winding having two magnetic circuits, a source of alternating current connected to said winding for setting up a variable flux in the respective magnetic circuits, a winding associated with each magnetic circuit and inductively related to the operating winding for superimposing magnetization thereon, and means for closing the circuit of either winding to cause one of the magnetic circuits to predominate and move the member.

3. An electromagnetic device for alternating current circuits, comprising a movable member having two positions, an operating winding having two magnetic circuits, a source of alternating current connected to said winding for setting up a variable flux in the respective magnetic circuits, a winding associated with each magnetic circuit to and inductively related to the operating winding to oppose the flux of theoperating winding, and means for energizlng either winding to cause the other magnetic circuit to predominate and move the member.

5. In a circuit controller, a magnetizing winding, a branched magnetic circuit therefor comprising a movable armature for controlling a circuit, means comprising secondary windings inductively related to the respective branches of said magnetic circuit for varying the relative amounts of flux in the two branches of said circuit, and means for including either of said secondary windings in a closed circuit.

"6. In a controller, an E-shaped core provided with a magnetizing winding on its middle leg and having a branched magnetic path through the other legs, a cooperating pivotedarmature, an auxiliary winding on each of the outer legs, and means for including either of the latter windings in a closed circuit. a

7. An electromagnetic device comprising a primary winding, a plurality of magnetic circuits therefor, a choke coil surrounding each magnetic circuit and means for rendering said choke coils alternately efiective.

8. n electromagnetic device comprising a core forming a plurality of magnetic cir cuits, a winding for setting up a Variable flux in each of said circuits, means associated with each circuit for setting up a flux therein opposing the flux due to the winding, means for varying the relative amounts of the opposing fluxes, and a circuitcontrolled by the variations in the relative amounts of c said opposing fluxes.

9. An electromagnetic device comprising a core forming a plurality of magnetic circuits, a winding for setting up a variable flux in each of said circuits, means associated with each circuit for setting up a flux therein opposing the flux due to the winding, means for varying the relative amounts of the opposing fluxes, and a member movable in response to the variations in the relative amounts of the opposing fluxes.

10. An electromagnetic device comprising a core forming a plurality of magnetic cirflux in each of said circuits, means assoclated witheach circuit for setting up a flux therein opposing the flux due to the winding, means for varying the relative amounts of the opposing fluxes, an armature forming' a part of said magnetic circuits and movable in response to the variations in the relative amounts of the opposing fluxes, and

a circuit controlled by the movement of said armature.

11. In a circuit controller, a core member, a winding for setting up in said core member two magnetic circuits, means for altercuits, a winding for setting up a variable nately choking back the flux in the respec- I tive magnetic circuits, and a movable member responsive to the flux changes in said magnetic circuits for controlling an electric circuit.

12. In a circuit controller, a core member, a winding for setting up in said core member two magnetic circuits, two damping coils associated with the respective magnetic circuits, means for alternately closing the circuits of the damping coils, and a movable member responsive to the flux changes of the respective magnetic circuits for controllin an electric circuit.

1 b witness whereof I have hereunto set my hand this 30th day of October, 1915.

TERRY T. I KING. 

